The present invention relates to a vehicular lamp unit, and more particularly to a projection lamp structure for a vehicular lamp unit of a type which produces a substantially parallel light beam from the light generated by a light source using an elliptic reflector and a projection lens.
A vehicular lamp such as a headlamp of an automobile produces a substantially parallel light beam from the light generated by a light source. Such headlamps include a type in which the light produced by a light source is formed into a substantially parallel beam by a parabolic reflector, and another type in which the light is made substantially parallel by a combination of an elliptic reflector and a projection lens. The latter type is a so-called projection lamp. Projection lamps are advantageous in that they can be made small in size but still produce a required light distribution pattern.
An example of projection lamp is disclosed in U.S. Pat. Nos. 4,685,036, 4,677,532 and 4,797,790, and is shown in FIG. 5. The conventional projection lamp is provided with an elliptic reflector 1 and a metal bracket 2 fixed to a front end of the reflector 1. A projection lens 4 is mounted on the bracket 2 through a holder member 3.
As is apparent from FIG. 5, the holder member 3, which is substantially box shaped, is fixed to the bracket 2 to support the projection lens 4. As a result, the conventional lamp unit is disadvantageous in that it requires a large space for accommodating the assembled box-shaped holder member 3. Further, the diameter of the bracket 2 must be relatively great. Thus, the conventional projection lamp is larger than desired.